WASHINGTON — Already under fire from officials in Florida, the administrator of the BP oil disaster fund is now facing criticism from the Obama administration, which has called the pace of filling claims "unacceptable."

The Gulf Coast Claims Facility "needs to devote whatever additional resources — or make whatever administrative changes — are necessary in order to speed up this process," Associate U.S. Attorney General Thomas J. Perrelli wrote in a letter to claims czar Kenneth Feinberg.

The criticism is notable because it comes from within President Barack Obama's administration, which hand-picked Feinberg to oversee the $20 billion provided by BP to compensate business owners and others who suffered from the oil spill.

"Your recent public statements have acknowledged that the process is more complicated and time intensive than you had anticipated," Perrelli wrote.

"I would reiterate to you, however, that the efficiency of the GCCF's review and payment process is not just a matter of fulfilling your own performance goals. The Deepwater Horizon Oil Spill has disrupted the lives of thousands upon thousands of individuals, often cutting off the income on which they depend. Many of these individuals and businesses simply do not have the resources to get by while they await processing by the GCCF."

Amy Weiss, a spokeswoman for Feinberg and the GCCF, said in a statement: "We received the letter and have been taking the necessary steps to accelerate paying claims. We have paid out as of last night $379,259,484 to 27,988 claimants in just 4 weeks."